We have to receive transcendental sound through the transcendental channel, therefore, Vedas are called Sruti. That means transcendental sound can be received through the ear. And by hearing this transcendental sound through the ear our heart becomes spiritually purified, and we can realize at that stage the transcendental Name, transcendental Qualities, transcendental Form, transcendental Pastimes etc. That is the way of descending process.
Because everything manifested is creation of the original transcendental Sound, therefore, factually everything is spiritual.
Letter to Hamsaduta dasa, 23 January, 1970